GB1591511A

GB1591511A - Herbicidally active 2-(dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid esters process for their manufacture and their use

Info

Publication number: GB1591511A
Application number: GB39093/77A
Authority: GB
Original assignee: Schering AG
Current assignee: Bayer Pharma AG
Priority date: 1976-09-30
Filing date: 1977-09-20
Publication date: 1981-06-24
Also published as: JPS5616791B2; US4183739A; DK410277A; IE45688L; JPS5344561A; FR2366287B1; FR2366287A1; DE2644425A1; LU78199A1; BE859271A; IT1084535B; IE45688B1; NL7710193A

Description

PATENT SPECIFICA Ti ON ( 11) 1591511

1 ( 21) Application No 39093/77 ( 22) Filed 20 Sept 1977 <> ( 31) Convention Application No2 644 425 ( 19) ( 32) Filed 30 Sept 1976 in C ( 33) Fed Rep of Germany (DE)

k C ( 44) Complete Specification published 24 June 1981

1 ( 51) INT CL 3 C 07 D 277/82 ( 52) Index at acceptance C 2 C 1390 200 202 213 220 226 22 Y 247 256 25 Y 30 Y 341 \ 34 Y 366 368 390 626 72 X 805 80 Y AA KD RB ( 54) HERBICIDALLY ACTIVE 2-(DIMETHYLCARBAMOYLIMINO)-BENZTHIAZOLIN3-CARBOXYLIC ACID ESTERS, PROCESS FOR THEI 1 R MANUFACTURE AND THEIR USE ( 71) We, SCHERING AKTIENGESELLSCHAFT, a Body Corporate organised according to the laws of the Federal Republic of Germany, of Berlin and Bergkamen, the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: 5

The present invention is concerned with new herbicidally active 2(dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid esters, with a process for the manufacture of these compounds and also with their use.

(Benzthiazol-2-yl)-urea derivatives having a herbicidal action have already been known (United States Patent Specification No 2,756,135) However, these 10 active substances have only a poor selective-herbicidal action.

The problem upon which the present invention is based has, therefore, been to develop an agent which has an excellent selective-herbicidal action.

This problem is solved in accordance with the present invention by the compounds of the general formula I, as defined below 15 The present invention accordingly provides compounds of the general formula I l-Cl-1 CH 3 (I) 7 <Ja = N-CO, in which R represents an aliphatic hydrocarbon group, a substituted aliphatic hydrocarbon group, an aromatic hydrocarbon group or a substituted aromatic 20 hydrocarbon group and X represents an oxygen or sulphur atom.

The compounds of the present invention are distinguished by an outstanding selective action towards crop plants and possess an excellent herbicidal action against mono and dicotyledonous weeds.

These compounds exhibit their selective action especially towards crop plants, 25 for example beetroot, bush bean, ground-nut, potatoes, peas, maize, rice, sorghum and cereals.

On the other hand, weeds and also weed grasses of the genera Stellaria, Senecio, Matricaria, Lamium, Centaurea, Amaranthus, Chrysanthemum, Ipomea, Polygonum, Alopecurus, Digitaria, Poa and others are especially advantageously combated 30 The rates of application for advantageous use are generally within the range of from 1 to 5 kg of active substance per ha When two or more compounds of the general formula I are used the range of 1 to 5 kg refers of course to the total amount applied of these compounds.

The present invention accordingly also provides a herbicidal preparation 35 which comprises a compound of the general formula I, in admixture or conjunction with a suitable carrier The preparation may of course contain one or more compounds of the general formula I.

2 1,591,511 2 The present invention further provides a method of protecting a living plant against weeds, wherein the area in the vicinity of the living plant is treated with a compound of the general formula I.

The present invention further provides a method of protecting a crop area against weeds, wherein the crop area is treated with a compound of the general 5 formula I.

The present invention further provides a pack which comprises a compound of the general formula I together with instructions for its use as a herbicide.

The compounds of the present invention may be used either alone, or in admixture with one another or with other active substances 10 In this connection, depending on the purpose desired, there are suitable, for example, the following herbicidally active substances, which, if desired, may be added to the compounds of the present invention immediately before use:

substituted anilines, substituted aryloxycarboxylic acids and also salts, esters and amides thereof, 15 substituted ethers, substituted arsonic acids and also salts, esters and amides thereof, substituted benzimidazoles, substituted benzisothiazoles, substituted benzthiadiazinone dioxides, 20 substituted benzoxazines, substituted benzoxazinones, substituted benzthiazoles, substituted benzthiadiazines, substituted biurets, 25 substituted quinolines, substituted carbamates, substituted aliphatic carboxylic acids and also salts, esters and amides thereof, substituted aromatic carboxylic acids and also salts, esters and amides thereof, substituted carbamoylalkyl-thio or dithio-phosphates, 30 substituted quinazolines, substituted cycloalkylamidocarbonthiolic acids and also salts, esters and amides thereof, substituted cycloalkylcarbonamido-thiazoles, substituted dicarboxylic acids and also salts, esters and amides thereof, 35 substituted dihydrobenzofuranyl sulphonates, substituted disulphides, substituted dipyridylium salts, substituted dithiocarbamates, substituted dithiophosphoric acids and also salts, esters and amides thereof, 40 substituted ureas, substituted hexahydro I H-carbothioates, substituted hydantoins, substituted hydrazides, substituted hydrazonium salts, 45 substituted isoxazolepyrimidones, substituted imidazoles, substituted isothiazolepyrimidones, substituted ketones, substituted naphthoquinones, 50 substituted aliphatic nitriles, substituted aromatic nitriles, substituted oxadiazoles, substituted oxadiazinones, substituted oxadiazolidinediones, 55 substituted oxadiazinediones, substituted phenols and also salts and esters thereof, substituted phosphonic acids and also salts, esters and amides thereof, substituted phosphonium chlorides, substituted phosphonalkylglycines, 60 substituted phosphites.

substituted phosphoric acids and also salts, esters and amides thereof, substituted piperidines, substituted pyrazoles, substituted pyrazolalkylcarboxylic acids and also salts, esters and amides thereof, 65 substituted pyrazolium salts, substituted pyrazolium alkyl sulphates, substituted pyridazines, substituted pyridazones, substituted pyridine carboxylic acids and also salts, esters and amides thereof, 5 substituted pyridines, substituted pyridine carboxylates, substituted pyridinones, substituted pyrimidones, substituted pyrrolidine carboxylic acids and also salts, esters and amides thereof, 10 substituted pyrrolidines, substituted aryl-sulphonic acids and also salts, esters and amides thereof, substituted styrenes, substituted tetrahydro-oxadiazinediones, substituted tetrahydromethanoindenes, 15 substituted tetrahydro-diazole-thiones, substituted tetrahydro-thiadiazine-thiones, substituted tetrahydro-thiadiazinediones, substituted thiadiazoles, substituted aromatic thiocarboxylic acid amides, 20 substituted thiocarboxylic acids and also salts, esters and amides thereof, substitutedthiolcarbamates, substituted thiophosphoric acids and also salts, esters and amides thereof, substituted triazines, substituted triazoles, 25 substituted uracils and substituted uretidinediones.

There may also be used other additives, for example non-phytotoxic additives which give a synergistic increase in action with herbicides, for example wetting agents, emulsifiers, solvents and oily additives 30 The active compounds of the general formula I or mixtures thereof are advantageously used in the form of herbicidal preparations, for example powders, strewable preparations, granules, solutions, emulsions or suspensions, with the addition of liquid and/or solid vehicles or diluents, and, if desired, of surface-active agents, for example wetting, adherent, emulsifying and/or dispersing agents 35 Suitable liquid carriers are, for example, water, aliphatic hydrocarbons, aromatic hydrocarbons, for example benzene, toluene and xylene, cyclohexanone, isophorone, dimethyl sulphoxide and dimethylformamide, and also mineral oil fractions.

As solid carriers there are suitable, for example, mineral earths, for example 40 tonsil, silica gel, talcum, kaolin, attaclay, limestone and silicic acid, and vegetable products, for example meals.

As surface-active agents there may be mentioned, for example, calcium lignin sulphonate, polyoxyethylene alkylphenyl ethers, naphthalene sulphonic acids and salts thereof, phenol sulphonic acids and salts thereof, formaldehyde condensates, 45 fatty alcohol sulphates and also substituted benzene sulphonic acids and salts thereof.

The proportion of the active substance or substances in the various herbicidal preparations may vary within wide limits For example, the preparations may contain from 10 to 80 % by weight of active compound(s), from 90 to 20 % by weight 50 of liquid or solid carrier and also, if desired, up to 20 % by weight of surface-active agent(s).

The application of the active compounds may be carried out in the usual manner, for example with water as carrier in quantities of spray liquor of about 100 to 1000 litres per ha It is also possible to apply the active compounds by the so 55 called "low volume" and "ultra-low volume" methods and, furthermore, they may be applied in the form of so-called microgranules.

Among the compounds of the present invention there are distinguished by an outstanding selective-herbicidal action especially those of the general formula I in which R represents an alkyl group containing I to 8 carbon atoms, an alkenyl group 60 containing 2 to 8 carbon atoms, an alkynyl group containing 2 to 8 carbon atoms, a phenyl group, a phenyl group substituted by one, two or three substituents selected from halogen atoms, alkyl groups containing I to 3 carbon atoms, alkoxy groups containing 1 to 3 carbon atoms, mono and di-alkylamino groups in which each alkyl group contains 1 to 3 carbon atoms and trihalogenomethyl groups, a phenyl 65 1,591,511 alkyl group in which the alkyl group contains I or 2 carbon atoms or a mono or dihalogeno-benzyl group and X represents an oxygen or sulphur atom.

Especially advantageous among the compounds of the general formula I are those in which R represents a methyl, ethyl, propyl, isopropyl, 2propenyl, 2propynyl, butyl, isobutyl, tert -butyl, sec -butyl, pentyl, isopentyl, hexyl, heptyl, 5 octyl, phenyl, chlorophenyl, dichlorophenyl, benzyl, chlorobenzyl or dichlorobenzyl group and X represents an oxygen or sulphur atom.

The new compounds of the present invention may be prepared, for example, by the process of the present invention, as defined below.

The present invention accordingly further provides a process for the 10 manufacture of a compound of the general formula I, wherein (a) a metal compound of the general formula l IO=N-O NX B(+) in which B represents a monovalent metal equivalent, preferably a lithium, sodium or potassium atom, is reacted with a halogeno-formic acid ester of the is general formula Hal-CO-X-R, in which R and X have the meanings given above and Hal represents a halogen atom, preferably a chlorine atom, or (b) l-(benzthiazol-2-yl)-3,3-dimethyl-urea of the formula 20 1 -co C is reacted in the presence of an acid-binding agent with a halogenoformic acid ester of the general formula Hal-CO-X-R, in which R, X and Hal have the meanings given above 25 The reaction of the components is preferably carried out at between 0 and C, but generally at room temperature For this synthesis of the compounds of the present invention the reactants are preferably used in substantially equimolar quantities As suitable reaction media there are preferred polar organic solvents.

Their choice depends on generally known considerations regarding the use of the 30 metal compounds, the halogeno-formic acid esters and the acid-binding agents used As solvents or suspension media there may be mentioned amongst many, for example, acid amides, for example dimethylformamide, acid nitriles, for example acetonitrile, ethers, for example dioxane, and ketones, for example acetone.

As acid-binding agents there may be used all the usual such agents For this 35 purpose there are suitable organic bases, for example tertiary amines, for example triethylamine or N,N-dimethylaniline, pyridine bases or suitable inorganic bases, for example oxides, hydroxides and carbonates of alkali and alkaline earth metals.

Liquid bases, for example pyridine, may serve simultaneously as solvents.

The final isolation of the compounds of the present invention so formed may 40 be carried out by distilling off the solvent used or by precipitation with water.

The starting materials for preparing the compounds of the present invention are known.

Some specific compounds of the present invention are listed in the following 1,591,511 Table:

1,591,511 TABLE.

Name of the compound 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid isopropyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3thiocarboxylic acid S-ethyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid methyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid butyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid ( 2-propenyl) ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid pentyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid isobutyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid ( 2-propynyl) ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid benzyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid phenyl ester Physical constant M.p: 105 C M.p: 138 C M.p: 134 C M.p: 80 C M.p: 102 C M.p: 69 C M.p: 89 C M.p: 136 C M.p: 137 C M.p: 148 C The compounds of the present invention are colourless and odourless crystalline products, which are insoluble in water and hydrocarbons, but dissolve moderately to readily in other organic solvents, for example halogenated hydrocarbons, ethers, ketones, alcohols, carboxylic acids, esters, carboxylic acid amides and carboxylic acid nitriles, and also many others.

The following Examples illustrate the invention Examples I and 2 illustrate the manufacture of the compunds of the general formula I and Examples 3 to 5 illustrate the possibilities of use of the compounds of the general formula I.

Example I.

20.44 Grams of the lithium salt of 2-(dimethylcarbamoylimino)benzthiazolin3-ide were suspended in 250 ml of acetonitrile, and 11 3 grams of chloroformic acid isopropyl ester were added dropwise at room temperature while stirring In order to complete the reaction the mixture was stirred for a further 30 minutes, and it was poured onto 1 5 litres of ice-water, and the precipitate that separated was filtered off with suction and recrystallized from isopropyl ether.

Yield: 17 1 grams ( 61 9 % of the theoretical yield) of 2(dimethylcarbamoylimino)benzthiazolin-3-carboxylic acid isopropyl ester melting at 105 C.

Analysis: Calculated C 54 70 % H 5 58 % N 13 67 % Found C 55 11 % H 5 98 % N 13 94 %.

Example 2.

Into a solution of 30 13 grams of 1-(benzthiazol-2-yl)-3,3-dimethyl-urea in 250 ml of pyridine were introduced dropwise while stirring at room temperature 16 95 grams of chloro-thioformic acid S-ethyl ester The solution, which was further stirred for 30 minutes, was introduced into 6-times its quantity of icewater, and the substance that separated, after being filtered off, was recrystallized from isopropyl ether There were obtained 26 35 grams ( 62 5 % of the theoretical yield) of 26 1,591,511 6 (dimethylcarbamoylimino) benzthiazolin 3 thiocarboxylic acid S-ethyl ester melting at 138 PC.

Analysis: Calculated C 50 46 % H 4 89 % N 13 58 % Found C 51 03 % H 5 01 % N 13 68 %.

Each of the other compounds of the present invention listed in the Table 5 above can be prepared in a manner analogous to that described in Example 1 or 2.

Example 3.

In a series of tests carried out in a greenhouse the compounds of the present invention listed in the following Table were each sprayed by the preemergence and post-emergence methods at a rate of application of 5 kg of active substance per 10 ha suspended in 600 litres of water per ha, on to Sinapis and Solanum as test plants.

Three weeks after the treatment the results of the treatment were evaluated, the results being expressed by a numerical scale extending from 0 to 4, the value 0 representing no action and the value 4 representing destruction of the plant.

As will be seen from the Table destruction of the test plants was generally 15 achieved.

Compound of the present invention 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid methyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid butyl ester 2-(Dimethy lcarbamoylimino)-benzthiazolin-3-carboxylic acid ( 2-propenyl) ester 2-(Dimethylcarbamoylimino)-benzthiazol in-3-carboxylic acid pentyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid isobutyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid isopropyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid ( 2-propynyl) ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid benzyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-thiocarboxylic acid S-ethyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid phenyl ester 0 = no action 4 = destruction of the plant Pre-emergence Sinapis Solanum Post-emergence Sinapis Solanum t1 'f L^ 8 1,591,511 8 Example 4.

In a series of tests carried out in a greenhouse the plants listed in the following Table were treated before their emergence with the agents being tested and listed in the Table at a rate of application of 1 kg of active substance per ha For this purpose the agents were in each case uniformly applied to the soil in the form of an 5 aqueous suspension using 500 litres of water per hectare The results show that the compounds of the present invention, as compared with the compound used for comparison, have a good selectivity.

The results are expressed by a numerical scale extending from O to 10, the value O representing destruction of the plant and the value 10 representing no 10 damage.

E 1:;: j r:

c LI 1) 3 ti ri 5 d;Z l.)t;:l c c E 1 3 c O U s 3 Cl 11) 010 2 >, '; 5 r 1 O O 5 G () z Z CL.

:: 4 j rj Pre-emergence Compound of the present invention :i O rd cc cn -51 Q) ri (n C 5 1 z 2 j R 1)2 r 3 C, rj -2 O ::t C a.

2-M ime thy le arb amoy 1 imino)-ben zth i az ol in3-carboxylic acid methyl ester 2-(Dimethylearbamoylimino)-benzthiazolin3-carboxylic acid butyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin3-carboxylic acid ( 2-propenyl) ester 2-(Dimethylearbamoylimino)-benzthiazolin3-carboxylic acid pentyl ester 2-(Dimethylearbamoylimino)-benzthiazolin3-carboxylic acid isobutyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin3-carboxylic acid isopropyl ester 2-(Dimethylcarbamoylimino)-benzthiazolin3-carboxylic acid ( 2-propynyl) ester 2 (Dimethylearbamoylimino)-benzthiazolin3-carboxylic acid benzyl ester 2-(Dimethylearbamoylimino)-benzthiazolin3-thiocarboxylic acid S-ethyl ester Agent used for comparison 1-(Benthiazol-2-yl)/e,e-dimethyl-urea Untreated 1 10 10 10 9 8 10 10 1 10 10 10 10 ' 8 8 10 1 10 10 10 10 10 1 10 10 10 10 8 8 10 1 8 10 10 10 10 1 8 9 8 9 1 10 10 8 8 10 10 10 1 9 10 8 8 9 8 1 10 10 10 10 10 10 10 1 9 8 2 9 8 4 9 10 10 10 10 10 10 0 O O O O 1 O O O 0 O O O O O O O O 0 O O O ' O O O O O 0 O O 00 '0 -0 00 0 O O O O O O O O 0 4 O O O O O O O 4 2 3 4 0 4 O 3 4 3 O O 0 O O O O O O O O 0 O O 2 1 O 1 -0 2 -0 ' (J 1 11 , (_ 1.

0 O 2 4 O 4 4 1 0 O O 10 10 10 IO l O l O IO 10 10 10 10 1,591,511 10 Notes to Table = not tested 0 = destruction of the plants = no damage Example 5.

In a series of tests carried out in a greenhouse the plants listed in the following Table were treated after their emergence with the listed agents being tested at a rate of application of 1 kg of active substance per ha For this purpose the agents 5 were in each case sprayed uniformly over the plants in the form of an aqueous suspension using 500 litres of water per hectare Also in this case, the compounds of the present invention exhibited three weeks after the treatment a high selectivity coupled with an excellent action against the weeds The agent used for comparison exhibited no selectivity 10 Again, the results are expressed by a numerical scale extending from O to 10, the value O representing destruction of the plant and the value 10 representing no damage.

r li 2 r:

CA) d Zl cj rn i >, cj "It C IDCJ Post-emergence Cd J-1 0 0 Cl.

.;O Q O w C cc 0 'n o :i Compound of the present invention -b 44 CO 0 c ri G 2 S C 3 .i c ri 74 2 l 3 U Q) L 11cn Q _j g ta :t t c ll; 2 Q) O ) c " ql) c M.

M O 2 M lz:l A 1 ti (n r 13ri C Z lu -$ 11 ZI 3 Rl ri;:t;S ri ri z: $ 11 3 cj 111 1 :: 'i j Tt i O $ 1 ri z Q) ru lQ) cn en zi CS 0 Q 2-M ime thy 1 carbarnoy 1 irnino) be nz th iaz ol in-3 -c arboxy 1 i c acid methyl ester 2-(Dimethylearbamoylirnino)benzthiazolin-3-carboxylic acid butyl ester 2-(Dimethylearbamoylimino)benzthiazolin-3-carboxylic acid ( 2-propenyl) ester 1 10 10 '10 8 10 10: 10 1 9 10 10 10 10, 10, 10 1 10 10 10 10, 10, 10 10 0 O ' O O O O ' O ' O O ' O 2 O ' O O ' 7 _ oLh 0 O 0 O' O O O O O O O O O 5 0 3 O O O O O O 1 'T 2 5 O 2-M ime thy lc arbamoy lirnino) benz thi az o 1 in-3 -carboxy 1 i c acid pentyl ester 2 (Dimethyliarbamoylimino)benzthiazolin-3-carboxylic acid isobutyl ester 1 10, 10 10 10 10 10 10 0 000 2 5 O 1 10 10 10 10 10 9 10 0 O O O O O: O O: 2 O 5 1 O 5 2-M i methyl carbamoy 1 imino)benz thiazolin-3 -carboxy li c acid isopropyl ester 1 8 10 10 9 10 10 10, 0 ' O O ' O ' O O O ' O O O 5 O ' O 2 1 r W O 0 1 F, -0 10 O Q) >, 1 r Cd O .S 'Pl Cd N C 34 M _ O 7; U to 0 O Cd 0 Cd -C m C 1)a 2 :: on i C 2 0 O O O ' O Go g c _j ri cl C z:2 -2 d z _z 1 , ti z z ri cj O U O CJ 1 C ru 010 j ' E 2 l El 2 I 5 I cj 0 O 2 U ', O L z -, LQ cn C M' E 1: Z CO Q) :z 4:

_z U li-:

E cj t 2 to 3 1 E ri -Z ::: Z cj ri 0 U z CJ 54 ct j:

O M j eel to -0 O cj i Compound of the present invention to cc 2-Wimethy lcarbamoyl imino)benz th iazol i n-3 -c arboxy 1 id acid ( 2-propynyl) ester 2-Mimethylcarbamoylimino)benzthiazolin-3-carboxylic acid benzyl ester 1 89 10 1088 10 100-0 O O 4 1 1 3 O 4 1 4 1 8 9 8 8 8 10 10 1 4 O O O 2 1 1 2 O 5 2-M imethy 1 carbamoy 1 imino) benz th i azo 1 in-3-thiocarboxy Ii c acid S-ethyl ester 1 9 10 10 10 10 8 10 10 3 O 2 2 4 4 O 3 1 Agent used for comparison 1 -(Ben z thiaz ol-2-y 1) -3,3 dimethyl-urea 1 15 1 5 4 5 O O O O O O 00 O O O O O O O 10 10 10 10, 10 10 10 10 10 10, 10 10 10 10 10 10 10 10 10 10 10 10 Untreated = not tested 0 = destruction of the plants = no damage

Claims

WHAT WE CLAIM IS:-

I 1 A compound of the general formula I H CO x R I (I) N,-a = N CO IH in which R represents an aliphatic hydrocarbon group, a substituted aliphatic hydrocarbon group, an aromatic hydrocarbon group or a substituted aromatic 5 hydrocarbon group and X represents an oxygen or sulphur atom.

2 A compound as claimed in claim 1, wherein R represents an alkyl group containing 1 to 8 carbon atoms, an alkenyl group containing 2 to 8 carbon atoms, an alkynyl group containing 2 to 8 carbon atoms, a phenyl group, a phenyl group substituted by one, two or three substituents selected from halogen atoms, alkyl 10 groups containing 1 to 3 carbon atoms, alkoxy groups containing 1 to 3 carbon atoms, mono and di-alkylamino groups in which each alkyl group contains I to 3 carbon atoms and trihalogenomethyl groups, a phenyl-alkyl group in which the alkyl group contains 1 or 2 carbon atoms or a mono or di-halogeno-benzyl group.

3 A compound as claimed in claim 1, wherein R represents a methyl, ethyl, 15 propyl, isopropyl, 2-propenyl, 2-propynyl, butyl, isobutyl, tert -butyl, sec -butyl, pentyl, isopentyl, hexyl, heptyl, octyl, phenyl, chlorophenyl, dichlorophenyl, benzyl, chlorobenzyl or dichlorobenzyl group.

4 2-(dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid isopropyl ester 20 2-(Dimethylcarbamoylimino)-benzthiazolin-3-thiocarboxylic acid S-ethyl ester.

6 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid methyl ester.

7 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid butyl ester.

8 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid ( 2-propenyl) 25 ester.

9 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid pentyl ester.

2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid isobutyl ester.

1 1 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid ( 2propynyl) 30 ester.

12 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid benzyl ester.

13 2-(Dimethylcarbamoylimino)-benzthiazolin-3-carboxylic acid phenyl ester.

14 A process for the manufacture of a compound as claimed in claim 1, wherein 35 (a) a metal compound of the general formula = N 7 C 11 C O Nw)CH 3 N O CO B in which B represents a monovalent metal equivalent, is reacted with a halogeno-formic acid ester of the general formula Hal-CO-X-R, 40 in which R and X have the meanings given above and Hal represents a halogen atom, or (b) I-(benzthiazol-2-yl)-3,3-dimethyl-urea of the formula 1,591,511 14 1,59 1,591,1 14 H _ 3 N A, N 11 CO-00is reacted in the presence of an acid-binding agent with a halogenoformic acid ester of the general formula Hal-CO-X-R, in which R, X and Hal have the meanings given above.

15 A process as claimed in claim 14, wherein B represents a lithium, sodium or 5 potassium atom.

16 A process as claimed in claim 14 or 15, wherein Hal represents a chlorine atom.

17 A process as claimed in claim 14, conducted substantially as described herein 10 18 A process as claimed in claim 14, conducted substantially as described in Example 1 or 2 herein.

19 A herbicidal preparation which comprises a compound of the general formula I given in claim 1, in which R and X have the meanings given in claim 1, in admixture or conjunction with a suitable carrier 15 A herbicidal preparation which comprises a compound as claimed in claim 2 or 3, in admixture or conjunction with a suitable carrier.

21 A herbicidal preparation which comprises the compound claimed in any one of claims 4 to 13, in admixture or conjunction with a suitable carrier.

22 A preparation as claimed in any one of claims 19 to 21, which is in the form 20 of a powder, a strewable preparation, granules, a solution, an emulsion or a suspension.

23 A preparation as claimed in any one of claims 19 to 22, containing a single compound of the general formula I in an amount of from 10 to 80 % by weight.

24 A preparation as claimed in any one of claims 19 to 22, containing two or 25 more compounds of the general formula T in a total amount of from 10 to 80 % by weight.

A preparation as claimed in any one of claims 19 to 24, containing a single surface-active agent in an amount of up to 20 % by weight.

26 A preparation as claimed in any one of claims 19 to 24, containing two or 30 more surface-active agents in a total amount of up to 20 % by weight.

27 Any one of the herbicidal preparations as claimed in claim 19 and substantially as described in Examples 3 to 5 herein.

28 A method of protecting a living plant against weeds, wherein the area in the vicinity of the living plant is treated with a compound of the general formula I given 35 in claim I, in which R and X have the meanings given in claim 1.

29 A method as claimed in claim 28, wherein the area is treated with the compound as claimed in claim 2 or 3.

A method as claimed in claim 28, wherein the area is treated with the compound claimed in any one of claims 4 to 13 40 31 A method as claimed in claim 28, wherein the area is treated with a herbicidal preparation as claimed in any one of claims 19 to 27.

32 A method as claimed in any one of claims 28 to 31, wherein a single compound of the general formula I is used for the treatment in an amount within the range of from I to 5 kg per hectare.

33 A method as claimed in any one of claims 28 to 31, wherein two or more compounds of the general formula I are used for the treatment in a total amount within the range of from I to 5 kg per hectare.

34 A method as claimed in claim 28, conducted substantially as described in Example 4 or 5 herein 50 A method of protecting a crop area against weeds, wherein the crop area is treated with a compound of the general formula I given in claim 1, in which R and X have the meanings given in claim 1.

36 A method as claimed in claim 35, wherein the crop area is treated with a compound as claimed in claim 2 or 3.

1,591,511 37 A method as claimed in claim 35, wherein the crop area is treated with the compound claimed in any one of claims 4 to 13.

38 A method as claimed in claim 35, wherein the crop area is treated with a herbicidal preparation as claimed in any one of claims 19 to 27.

39 A method as claimed in any one of claims 35 to 38, wherein a single compound of the general formula I is used for the treatment in an amount within the range of from 1 to 5 kg per hectare.

A method as claimed in any one of claims 35 to 38, wherein two or more compounds of the general formula I are used for the treatment in a total amount within the range of from I to 5 kg per hectare 10 41 A pack which comprises a compound of the general formula I given in claim 1, in which R and X have the meanings given in claim 1, together with instructions for its use as a herbicide.

42 A pack which comprises a compound as claimed in claim 2 or 3 together is with instructions for its use as a herbicide is 43 A pack which comprises the compound claimed in any one of claims 4 to 13 together with instructions for its use as a herbicide.

ABEL & IMRAY, Chartered Patent Agents, Northumberland House, 303-306 High Holborn, London WC 1 V 7 LH.

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1981.

Published by the Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.

I 1,591,511